Reticulated Platelets in Medicine: Current Evidence and Further Perspectives.

Noé Corpataux,Willibald Hochholzer,Christian Marc Valina,Kilian Franke,Franz-Josef Neumann,Alexander Kille,Thomas Nührenberg

doi:10.3390/jcm9113737

Noé Corpataux, Willibald Hochholzer + Show 5 more

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https://doi.org/10.3390/jcm9113737

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Abstract

Reticulated platelets (RPs) are young thrombocytes, newly released from the bone marrow. The identification and quantification of these cells remained difficult for decades due to a lack of standardized preanalytical and analytical methods. With the introduction of automated hematology analyzers in clinical routine, the determination of RPs, either as a total count or as a fraction, became more reliable, faster and more affordable. Currently, RPs are the focus of research in multiple clinical settings. In cardiovascular medicine, recent studies have focused on the relationship between RPs, coronary artery disease (CAD) and clinical outcomes, as well as the impact of RPs on the effects of antiplatelet therapy. Cohort studies showed increased levels of RPs in patients with acute coronary syndrome (ACS) or cardioembolic stroke. In patients with ACS, increased levels of RPs were also associated with an increased incidence of major ischemic cardiovascular events during follow-up. Further studies showed an association of levels of RPs with the antiplatelet response to less-potent P2Y12 inhibitors. In patients with paroxysmal atrial fibrillation undergoing pulmonary vein isolation, levels of RPs differed significantly depending on the achieved rhythm (sinus rhythm vs. recurrent atrial fibrillation). Levels of RPs appear to also be predictive for bleeding events in patients with various hematological diagnoses. Although no causal relationship has so far been proven, RP values have been associated with a large number of pathologies and clinical scenarios. This review summarizes the current evidence with regard to RPs and their potential diagnostic and prognostic value for noncardiovascular patients and for cardiovascular patients in particular. It describes further perspectives on how the testing of these cells might improve the treatment of cardiovascular patients.

Highlights

Reticulated platelets (RPs) are platelets which have been newly released from the bone marrow
In analogy to reticulocytes in erythropoiesis, these platelets were named reticulated platelets [1,2]. These cells, which according to various studies might have an increased reactivity, are larger than mature platelets and contain more ribonucleic acid (RNA) (Figure 1), which was thought to be a vestigial remnant of megakaryocytic RNA [3,4]
RPs were first used in clinical decision-making for hematologic disorders, where these cells were used as a surrogate parameter of megakaryopoiesis in order to differentiate primary from secondary thrombocytopenia

Summary

Introduction

Reticulated platelets (RPs) are platelets which have been newly released from the bone marrow. In analogy to reticulocytes in erythropoiesis, these platelets were named reticulated platelets [1,2] These cells, which according to various studies might have an increased reactivity, are larger than mature platelets and contain more ribonucleic acid (RNA) (Figure 1), which was thought to be a vestigial remnant of megakaryocytic RNA [3,4]. SYTO 13 staining remains stable over time, allowing longer sorting times, and has shown a good correlation with the fraction values from the Sysmex automated analyzer, which is not the case for thiazole orange [20] While these more sophisticated methods enable the analysis of specific features of RPs such as a prothrombotic transcriptomic profile, the automated determination of RPs appears to be. Med. 2020, 9, 3737 the preferable quantification method for clinical use given its highly standardized testing approach, which allows the comparison of results between different cohorts [19,21]

Immature Platelets and Noncardiovascular Diseases

Immature Platelets and Cardiovascular Disease

Future Perspectives